The present invention relates to a process for producing 1,1,1-trifluoroacetone, which is useful as an intermediate of pharmaceuticals and agricultural chemicals, or as a reagent for introducing fluorine-containing groups.
Japanese Patent Laid-open Publication 2000-336057, corresponding to U.S. Pat. No. 6,262,312, discloses a process for industrially producing 1,1,1-trifluoroacetone by subjecting a halogenated trifluoroacetone, which is represented by the formula [1], to a reduction treatment in the presence of a metallic zinc (as a reducing agent) and a protonic solvent, 
where X represents a chlorine, bromine or iodine, and n represents an integer from 1 to 3.
Japanese Patent Laid-open Publication 2001-316322, corresponding to U.S. Pat. No. 6,340,776, discloses another process for producing 1,1,1-trifluoroacetone without necessity of using a large amount of metallic zinc. In this process, a halogenated trifluoroacetone of the formula [1] is subjected to a hydrogenolysis in a gas phase using a solid-phase catalyst containing a particular transition metal, while the halogenated trifluoroacetone is kept in a vaporized condition. It is disclosed in this publication that an example of the halogenated trifluoroacetone is 1,1-dichloro-3,3,3-trifluoroacetone.
Japanese Patent Laid-open Publication 10-287609 discloses a first process for producing 1,1-dichloro-3,3,3-trifluoroacetone by fluorinating pentachloroacetone by hydrogen fluoride in a liquid phase in the presence of an antimony catalyst.
Japanese Patent Laid-open Publication 11-001451 discloses a second process for producing 1,1-dichloro-3,3,3-trifluoroacetone by fluorinating pentachloroacetone by hydrogen fluoride in a gas phase in the presence of an aluminum catalyst.